“DOPADRUG” project

This project is a consortial cooperation with Delta Informatics, Inc. and Semmelweis University. Our aim is to cost-effectively design dopaminergic drug candidates with an antidepressant or antipsychotic effect using the self-developed in silico drug profile method and a novel in vivo test system based on transgenic Caenorhabditis elegans strains expressing human dopaminergic receptors.

The method we used for in silico selection of potential dopaminergic drug candidates is presented here. Using this method, we selected new potential dopaminergic drug candidates from among two millions of small molecules of the ZINC database. The dopaminergic effect of the candidates which looked promising based on the in silico predictions was further tested using an in vivo test system developed within the framework of the present project, and was finally validated by in vitro binding assays performed by an independent company.

Development of transgenic C. elegans test system expressing human dopamine receptors
During the development and testing of drug candidate molecules, in vivo preclinical tests can made up a significant proportion of the development costs. One of the main reasons for this is the relatively long lifespan of model animals (primarily mice and rats) as well as the complexity of their nervous system. Another crucial factor is that animal protection laws are becoming stricter and stricter. Therefore, the development of new and fast in vivo test systems – to significantly reduce the time spent on preclinical testing as well as to cut back on development costs – is one of the greatest challenges for modern pharmaceutical research. We developed a novel in vivo test system based on one of the most generally used genetic model organisms, Caenorhabditis elegans. The nervous system of C. elegans is relatively simple (it is made up of 302 neurons – out of which eight are dopaminergic neurons), which makes it an ideal candidate for both physiological and genetic research/assays. This particular animal has a very short life span: approx. 10 days at room temperature. We generated transgenic C. elegans strains which express various types of human dopamine receptors. These strains are well suited to test the potential dopaminergic effects of the molecules we identified in silico. By using strains containing various types of dopamine receptors, it is possible to determine the dopaminergic profile of drug candidates in vivo. The structure and the cost of this test is similar to that of HT GPCR (high-throughput G protein-coupled receptor) binding assays using stable cell lines, however the former is much more advantageous in that binding and its physiological effects can be tested on the intrasynaptic receptors of a whole organism. Currently, these properties can only be examined during a later, much more expensive stage of drug development.

 

 

For the automated evaluation of a large number of data, we developed a digital image analysis system which can be incorporated into existing HT systems. δVision is an image manipulation, image processing and analyzer scientific software. It was developed especially for the identification and tracking of C. elegans worms, using Java SE technology. The system is based on a central database that stores the collected snapshot data and some more information essential for the run. Client computers can connect to the central server, thus work can be done in different places simultaneously.